I have had my pacemaker for almost 2 years. Very simple procedure. You can feel it under the chest. The only visibility to others is a small scar that fades with time. Healing is variable, I assume, with different people. I was given a sheet that outlined things to do and not do with a timeline. Initial healing takes a couple of months. I do strength training including deadlifts weighted squats and bench press. I did nothing for 8 weeks. When I returned to the gym, I was scared but I took everything very slowly starting with basic body work. When I began weights again, I started very low. I have a trainer so I was supervised but the guideline has always been to listen to your body and proceed gradually. For the most part, I don't notice the pacemaker. I do get discomfort sometimes but I've never had pain. I also do Zumba/occasional Yin Yoga and have never had a problem.

My reason for a pacemaker was bradycardia. I had all the classic symptoms: fatigue, shortness of breath, little dizziness after some exercises. My heart rate was 31 when I went to the hospital. I don't think it is an exaggeration to say that the pacemaker gave me back my life. My pacemaker is a Medtronic. They have a good website for patients and an excellent 'call with your question' line. I assume other manufacturers have resources too.

Hope this helps